for engineers

Engineering phenomenon:
the nuts and bolts behind the success of deep lake water cooling.

Thanks to a coincidence of geographical providence, global energy instability and local political astuteness, Toronto’s central business district today finds itself in enviable circumstances. It was decades ago when the notion of using the icy waters from deep in Lake Ontario as a source of air conditioning for buildings in the city’s core was first hatched. Now an operational reality, Enwave’s Deep Lake Water Cooling system is at full capacity.

Many engineering firsts

DLWC is the world’s first example of deep water cooling on a district energy scale. Its magnitude is unprecedented. Three 5 km-long intake pipes, with individual sections pre-assembled, were floated to and then sunk to the lake bed at a depth of 84m, where the water remains within a uniformly cool temperature range. Some 12 km of underground pipe was installed beneath the city’s core to serve as a distribution network. At the time of order, the DLWC project had specified the largest set of heat exchangers ever used in Canada. The quality of equipment and technical standards adhered to were very high.

And yet the system’s operation is elegantly simple: The harnessing of an abundant, natural and renewable resource that has existed at Toronto’s doorstep for thousands of years.

Huge economic appeal completes the package

The DLWC system also offers a persuasive set of benefits that makes it extremely attractive to building owners. Because Lake Ontario serves as the engine of cooling, DLWC eliminates the need for electrically-powered chillers at customers' buildings. This saves tens of thousands of dollars in capital investments at new constructions, while freeing significant square footage and reducing maintenance and replacement costs for retrofits at existing buildings. The environmental factors are also significant and include: reduced carbon emissions, elimination of CFC-damaging coolants, reliance on a clean, renewable resource, and the fact that no heat is rejected back into the lake.